JP2022036121A - Kink resistant graft - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a favorable stent graft and the like.

SOLUTION: A kink resistant stent graft includes a graft forming a tube with a central lumen extending from a first end of the tube to a second end of the tube, and a stent secured to the graft adjacently to the first end of the tube. The graft includes a corrugated inner graft layer forming at least a middle portion of the tube, and an outer graft layer covering the corrugated inner graft layer.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2022,JPO&INPIT

Description

Cross-reference to related applications This application claims the interests of US Provisional Patent Application No. 62 / 372,031 filed August 8, 2016, which is incorporated herein by reference in its entirety.

Technical Fields The present disclosure generally relates to implantable artificial organs, including implantable internal artificial organs such as grafts and stent grafts.

Background Aneurysms occur in blood vessels where the strength or elasticity of the blood vessel wall is insufficient to prevent the wall from expanding or stretching with the passage of blood due to the patient's age, disease or genetic predisposition. .. If the aneurysm is left untreated, the walls of the blood vessels can dilate and rupture, often leading to death.

To prevent rupture of the aneurysm, a stent graft can be percutaneously introduced into the blood vessel and deployed across the aneurysm sac. Stent grafts include graft fabrics secured to a cylindrical scaffold or skeleton of one or more stents. The stent can help provide the radial outward force required to form a seal between the graft and the healthy portion of the vessel wall and can provide migration resistance. Blood flowing through the blood vessel is guided through the luminal surface of the stent graft and can be reduced without removing the stress on the blood vessel wall at the location of the aneurysm sac. Stent grafts may reduce the risk of rupture of the vessel wall at the site of the aneurysm and allow blood to flow through the vessel without interruption.

Aneurysms that occur in the aorta, which is the largest artery of the human body, may occur in the chest (thoracic aortic aneurysm) or in the abdomen (abdominal aortic aneurysm). The curvature of the aortic arch can make thoracic aortic aneurysms particularly difficult to treat. Other parts of the vascular structure, such as the common iliac artery extending from the aorta, may also meander. Therefore, stent grafts deployed in such areas are preferably capable of adapting to the vascular structure. A high degree of compatibility can help, for example, to bend the stent graft and optimally juxtapose it to seal the original vessel.

Abstract The present disclosure generally relates to a corrugated graft layer that includes a stowed length as a corrugation and a kink-resistant graft that includes a second graft layer covering the corrugated graft layer. The dilation of the waveform at the lateral radius of the curvature allows such a kink-resistant graft to resist kink when implanted within the curvature of the patient's vasculature, such as the thoracic aorta.

In one variant, the kink-resistant stent graft is a graft forming a tube with a central lumen extending from the first end of the tube to the second end of the tube, and the first of said tubes. Includes a stent anchored to the graft adjacent to the end of the. The graft includes a corrugated inner graft layer that forms at least the middle of the tube and an outer graft layer that covers the corrugated inner graft layer.

In some examples, the corrugated medial graft layer extends from the first end of the tube to the second end of the tube. In some such examples, the outer graft layer extends from the first end of the tube to the second end of the tube.

In the same or different examples, the corrugations provide a corrugated inner graft layer with a storage length of at least 25 percent.

In the same or different examples, the corrugations provide a corrugated inner graft layer with a storage length of at least 50 percent.

In the same or different example, at least one of the corrugated inner and outer graft layers is formed from stretched polytetrafluoroethylene (ePTFE) film.

In the same or different examples, the outer graft layer is formed from a stretchable film.

In the same or different examples, the corrugated inner and outer graft layers are coupled to each other.

In the same or different example, the graft is configured to maintain at least 60% of its cross-section at the apex of a 90 degree bend while receiving an internal fluid pressure of at least 100 mmHg. It is configured to resist kink while undergoing a 90 degree bend at an internal fluid pressure of 100 mmHg.

In the same or different example, the middle part of the tube between the first end and the second end does not contain a stent, the middle part having a length at least twice the outer diameter of the middle part. ..

In the same or different example, the inner diameter of the tube is at least 12 mm.

In the same or different example, the stent is a self-expanding stent.

In the same or different example, the stent is the first stent and the kink resistant stent graft further comprises a second stent anchored to the graft adjacent to the second end of the tube.

In another variant, the method of forming a kink-resistant graft wraps the film to form a tube with a central lumen that extends from the first end of the tube to the second end of the tube. Forming a corrugated inner graft layer, crushing the inner graft layer to form a corrugation in the inner graft layer, where the corrugation provides a corrugated inner graft layer with a storage length of at least 25%. The outer graft layer is wrapped on the corrugated inner graft layer to cover the corrugated inner graft layer, and the outer graft layer is joined to the corrugated inner graft layer to form a kink-resistant graft. Including that.

In the same or different example, this method further comprises immobilizing a stent on the graft adjacent to the first end of the tube.

In some examples, wrapping the film to form the inner graft layer forming the tube involves wrapping more than one layer to form the tube.

In the same or different example, this method wraps the film to form the inner graft layer forming the tube, but then before crushing the inner graft layer to form a corrugation in the inner graft layer. It further comprises heating the film to cure the film in a tube (set).

In the same or different example, this method further comprises wrapping the outer graft layer onto the corrugated inner graft layer to cover the corrugated inner graft layer and then joining the wrapped outer graft layer to the corrugated inner graft layer. include.

In the same or different example, the kink-resistant graft is configured to maintain at least 60% of its cross-section at the apex of a 90 degree bend while receiving an internal fluid pressure of at least 100 mmHg. It is configured to resist kink while undergoing a 90 degree bend at an internal fluid pressure of at least 100 mmHg.

In the same or different examples, the kink resistant graft has a wall thickness of 0.20 nm or less.

Although a plurality of examples have been disclosed, still other examples of the invention will be apparent to those skilled in the art from the following detailed description showing and illustrating exemplary examples of the invention. Therefore, the drawings and detailed description should be considered to be exemplary and not limiting in nature.

Brief Description of the Drawings The accompanying drawings are included to provide a further understanding of the present disclosure, which are incorporated herein by reference and constitute an example thereof, providing examples of the present disclosure and the principles of the present disclosure along with the description. Helps to explain.

1A and 1B show kink-resistant stent grafts.

2A-2E show exemplary techniques for forming a kink-resistant stent graft on a mandrel.

Detailed Description Aneurysms that occur in areas of the anatomical structure of meandering blood vessels can be difficult to repair using grafts or stent grafts. On the other hand, inclusion of the stent along the length of the graft resists kink and helps maintain the inner diameter of the stent graft being bent at the treatment site according to the anatomy of the blood vessel at the treatment site. Can be done. However, such stents can cause unwanted pressure on the walls of the vasculature. Stent elements placed in close proximity to each other along the length of the graft can further limit the bending radius of the stent graft in that adjacent stent elements can interfere with each other along the inner diameter of the bend. In addition, the absence of stent elements placed in close proximity along the length of the graft can cause the graft material to kink adjacent to the bend. In addition, minimally invasive implant techniques require close densification of internal prostheses during delivery to the treatment site. In various examples, the stent element of a stent graft may not be as compact as the graft material of the stent graft.

1A and 1B show the kink resistant stent graft 100. The stent graft 100 includes a graft 110, which forms a tube with a central lumen from the first end of the tube to the second end of the tube. As described in more detail with respect to FIGS. 2A-2E, the stent graft 100 includes a corrugated inner graft layer 106 (FIG. 2C) forming at least the middle portion of the tube and an outer graft layer covering the corrugated inner graft layer. Includes 108 (FIG. 2D).

The corrugated inner graft layer 106 includes the stowed length as a corrugated form. Waveforms can also be described as convolutions, creases, swells, wrinkles, etc. As shown in FIG. 1B, when implanted inside the curvature of a patient's vasculature, such as the thoracic aorta, the stent graft 100 resists kink by expanding or extending the waveform at the outer diameter of the curvature. Enables. By resisting the kink, the design of the graft 110 may limit the need for a stent element inside the middle part of the graft 110, or other part of the graft 110 that corresponds to the corrugation. The stent graft 100 can adapt to the anatomy of a tortuous vessel without kinking, while also facilitating tight densification for intravascular delivery to the treatment site. It should be understood that while various examples have an intermediate portion with a corrugation, other examples include either an end with a corrugation or an intermediate portion characterized by the absence of a corrugation.

Further, potential materials for graft members include, for example, fluoropolymers such as stretched polytetrafluoroethylene (ePTFE), polyesters, polyurethanes, perfluoroelastomers, polytetrafluoroethylene, silicones, urethanes, ultrahigh molecular weight polyethylenes. , Aramid fibers and combinations thereof. Other examples of graft member materials include high-strength polymers such as ultra-high molecular weight polyethylene fibers (eg, Spectra®, Dyneema Purity®, etc.) or aramid fibers (eg, Technora®, etc.). Fibers can be mentioned.

In addition to the graft 110, the stent graft 100 is attached to the stent element 120 fixed to the graft 110 adjacent to the first end of the tube of the graft 110 and to the graft 110 adjacent to the second end of the tube. Further includes a immobilized stent element 121. Stent elements 120, 121 may function to seal the lateral end of the stent graft 100 inside the vessel wall in order to direct blood flow beyond the aneurysm within the vessel wall. In various applications, the middle part of the tube of the graft 110 does not include any stent. In some examples, this intermediate portion can have a length of at least twice the outer diameter of the tube of the intermediate portion graft 110.

As shown, the stent graft 100 includes two stent elements 120 and two stent elements 121. In another example, the stent element 120 can contain one or more than two stent elements, and the stent element 121 can contain one or more than two stent elements. Further, the stent element 121 does not have to include stent elements at both ends such that the stent element is located only at, for example, the upstream end of the graft 110, the middle portion of the graft 110, or the downstream portion of the graft 110. Is an optional element. Stent elements 120, 121 may indicate a self-expandable stent element and may be formed from a shape memory alloy such as nitinol, or stent elements 120, 121 may indicate a balloon expandable stent element, such as stainless steel. It can be formed from the biocompatible material of.

The stent graft 100 is constrained to a radially folded form and can be releasably attached to a delivery device such as a catheter assembly. The diameter of the stent graft 100 in the folded configuration is small enough for the stent graft 100 to be delivered to the therapeutic area through the vasculature. In the folded configuration, the stent graft 100 can be carried or passed by the catheter shaft through the vasculature to the therapeutic area. In the expanded configuration, the diameter of the stent graft 100 can be approximately the same as the vessel to be repaired. In another example, the diameter of the stent graft 100 in the dilated configuration may be slightly larger than the vessel being treated to result in a traction fit within the vessel.

In various examples, the stent graft 100 can include self-expandable devices such as self-expandable stent grafts. Such devices extend from a radially folded configuration to a radially expanded configuration when unconstrained. In another example, the stent graft 100 can include a device that is expanded with the help of a secondary device, such as a balloon.

In some specific examples, the stent graft 100 is a dilated internal prosthesis used to treat an abdominal aortic aneurysm such that the stent graft 100 is configured to seal the weakened wall of the aorta. be able to. Delivery to the treatment site can be via the femoral or iliac arteries of the thigh. Bending and angle of such vasculature can cause difficulties, which are alleviated by the design of the stent graft 100.

In various examples, the stent graft 100 can include a fenestable portion. In such a configuration, the stent graft 100 can include a fragile material that can be fenestrated by an intraluminal tool after the stent graft 100 has been partially or completely implanted in the patient's vasculature. Once the window is opened, the fenestable portion can be used to attach a bifurcated stent graft to, for example, the stent graft 100. Lateral fenestrations allow bifurcation devices such as bifurcated stent grafts to be connected or communicated with the stent graft 100. Such fenestration and bifurcation stent grafts can facilitate the adaptation of the stent graft 100 and additional bifurcation stent grafts to the patient's anatomy such as the thoracic aorta and adjacent vascular branches. In some of these examples, the stent graft 100 can have a tube inner diameter of at least 12 millimeters (mm). In the same or different example, the stent graft 100 can have a tube length of graft 110 that is at least twice as long as its inner diameter. In one particular example, the inner diameter of the tube of the graft 110 can be about 15 mm and the length of the tube of the graft 110 can be about 37 mm. Of course, any dimension may be selected according to the requirements of the patient's therapeutic area. In some examples, the surgeon may have a set of stent grafts, such as the Stent Graft 100 of various sizes, to allow selection of the size that best fits the patient's anatomy.

In various examples, the stent elements 120, 121 and / or the graft 110 can include a therapeutic coating. In these examples, the inside and / or outside of the stent component and / or graft member can be coated, for example, with the CD34 antigen. Furthermore, among others, for example, heparin, sirolimus, paclitaxel, everolimus, ABT-578, mycophenolic acid, tachlorimus, estradiol, anoxic radical scavenger, biolimus A9, anti-CD34 antibody, PDGF receptor blocker, MMP-1 receptor blocker. Coat the graft member with any number of drugs or therapeutic agents, including drugs, VEGF, G-CSF, HMG-CoA reductase inhibitors, iNOS and eNOS stimulants, ACE inhibitors, ARBs, doxicyclins and salidomides. Can be used for.

A 90 degree bent stent graft 100 without kink is shown in FIG. 1B. As shown in FIG. 1B, the dilation of the waveform at the lateral radius of the curvature allows the stent graft 100 to resist kink when implanted within the curvature of the patient's vasculature, such as the thoracic aorta. By resisting the kink, the design of the graft 110 can limit the need for a stent element in the middle of the graft 110. The stent graft 100 can adapt to the anatomy of a tortuous vessel without kinking, while facilitating tight densification for intravascular delivery to the treatment site.

The fluid pressure from the blood flowing through the expanded stent graft 100 can further help prevent kink when the stent graft 100 is bent as shown in FIG. 1B. The fluid pressure can help release the stored length of the corrugation of the corrugated layer 106 at the outer radius of the bend. For example, the stent graft 100 is configured to maintain at least 60% of its cross-sectional area at the apex of a 90 degree bend while the graft 100 receives an internal fluid pressure of at least 100 millimeters of mercury (mmHg). It can be configured to resist kink while undergoing a 90 degree bend at the internal fluid pressure of millimeter mercury (mmHg). 100 mmHg is similar to mean human blood pressure and is therefore an approximate representative of the pressure experienced by the stent graft 100 when implanted within the patient's vasculature.

2A-2E show exemplary techniques for forming a kink-resistant stent graft 100 on Marendre 200. The mandrel 200 is a tubular element suitable for supporting receiving various layers of the stent graft 100. The mandrel 200 is also suitable for supporting various layers of the stent graft 100 during heat treatment, if desired. As described herein, the use of the mandrel 200 is made as needed, as any suitable technique can be used to form the layer of the stent graft 100.

As shown in FIG. 2A, the tube layer 102 is placed on the mandrel 200. For example, the tube layer 102 can be an ePTFE film tube, which is then stretched over the mandrel 200. The outer diameter of the mandrel 200 is close to the inner diameter of the graft 110. In one particular example, the tube layer 102 can be an ePTFE film tube with an average inner diameter of about 11.5 mm and the mandrel 200 can have an outer diameter of about 15 mm. In the same or different examples, the outer diameter of the mandrel 200 and the resulting tube diameter can vary over the length of the tube. For example, the mandrel 200 can provide a tapered profile with a larger diameter at one end compared to the other end.

The film layer 104 is then wrapped onto the tube layer 102, as illustrated in FIG. 2B. After wrapping the film layer 104 to form the inner graft layer forming the tube, the wrapped film layer 104 is heated before crushing the inner graft layer to form a corrugation in the inner graft layer. The wrapped film layer 104 can be heated and cured to form a tube more permanently, and / or the wrapped film layer 104 can be joined to the tube layer 102. As shown, the film layer 104 is a spiral wrap, but the film layer may be oriented or a combination of orientations of the wraps in any direction, eg, longitudinal wraps and tobacco wraps. The tube layer 102 and the film layer 104 form an inner graft layer forming a tube with a central lumen from the first end of the tube to the second end of the tube.

The tube layer 102 and the film layer 104 show an example of an inner graft layer, but any various wrapped layer and / or tube layer can form an inner graft layer, the inner graft layer being the tube layer 102. Includes only one or more tube layers such as, only one or more wrapped layers such as film layer 104, or any combination of tube layer and wrapped layer. The tube layer 102 and / or the film layer 104 can be formed from an ePTFE film or other suitable graft material. In an example formed from ePTFE, one or both of the tube layer 102 and / or the film layer 104 may have an average wall thickness of about 0.08 nm, such as an average wall thickness of 0.10 nm or less, or 0.20 nanometers. Each can have a single layer average wall thickness of (nm) or less.

The tube has a length of 202. Optionally, the assembly of the tube layer 102 and the film layer 104 may be heated to join together. The tube layer 102 and the film layer 104 represent an example of an inner graft layer, but any graft material of any number of layers can be used according to the desired properties of the graft 110.

As shown in FIG. 2C, the inner graft layer is crushed from length 202 to length 204 to form a corrugation in the inner graft layer, forming a corrugated inner graft layer 106, and the corrugation is the storage length of the corrugated inner graft layer 106. Give. The storage length is the ratio of the length 204 to the length 202. For example, the storage length can be at least 25 percent, at least 40 percent or at least 50 percent. In some specific examples, the storage length can be about 50 percent. Generally speaking, kink resistance and wall thickness increase with storage length, while flexibility and suitability for intravascular delivery decreases with storage length.

In one technique for forming a retracted length in the graft layer, a tube that would otherwise have a relatively smooth surface is crushed, but other techniques may be used. For example, a graft layer, such as an inner graft layer, can be formed on a mandrel having surface features instead of the tube layer 102 and film layer 104, the surface features being retracted length when the graft layer is removed from the mandrel. I will provide a. As another example, such an inner graft layer can be formed from a material containing microstructures including storage length. An example of a material containing microstructures, including storage length, is House et al., US Pat. No. 5, entitled "RAPIDLY RECOVERABLE PTFE AND PROCESS THEREFORE". A porous PTFE material having a microstructure containing nodes interconnected by fibrils having a curved or wavy appearance as disclosed in 308,664, the entire contents of which are by reference for all purposes. Incorporated herein. As another example, such an inner graft layer may be the elastic material of U.S. Patent Application Publication No. 2014/0135597 by Cully et al., Named the invention "ELASTIC STENT GRAFT". , Can be formed from an elastic material that provides a retention length, the entire contents of which are also incorporated herein by reference for any purpose. In some examples, such elastic materials are held in a compressed state by the outer graft layer prior to implant and release the retracted length outside the bend upon deployment. In another example, such elastic material may be stretched outside the bend during deployment. Any other technique for creating a retracted length in the graft layer can also be used.

In some examples, the waveform can be relatively consistent along the length of the graft. Such an example may provide simplified manufacturability as the graft can be manufactured and then cut to a certain size without considering the characteristics changing along the length of the graft prior to cutting. .. In another example, the corrugation may be limited to a specific portion of the graft, such as a portion that is expected to undergo bending. In the same or different examples, the waveform itself may vary along the length of the graft. For example, larger amplitude and / or frequency waveforms can be placed towards the middle of the graft, while smaller amplitude and / or frequency waveforms can be placed beyond the middle.

As shown in FIG. 2D, the outer graft layer 108 is arranged on the corrugated inner graft layer 106 so as to cover the corrugated inner graft layer 106. As shown, the outer graft layer 108 is a cigarette wrap, but the film layer may be any wrap orientation or combination of orientations such as longitudinal wraps or spiral wraps. The outer graft layer 108 can be formed from an elastic film to facilitate stretching at the outer radius during bending of the graft 110. For example, the outer graft layer 108 can be formed from an ePTFE film or other suitable graft material.

In some examples, the corrugated inner graft layer 106 and the outer graft layer 108 can each extend to the length of the tube of the graft 110. In another example, the corrugation of the inner graft layer 106 may be limited to a selected portion of the tube, such as the central portion of the tube. Such an example can provide a smaller folded profile for the stent graft 100, as the corrugated thickness of the inner graft layer 106 does not have to overlap with the stent elements 120, 121.

After wrapping the outer graft layer 108 on the corrugated inner graft layer 106 to cover the corrugated inner graft layer 106, the outer graft layer 108 can be joined to the corrugated inner graft layer 106 to form the kink resistant graft 110. .. For example, by heat treating the assembly with the outer graft layer 108 and the corrugated inner graft layer 106, for example, by heating the assembly, or by massaging the outside of the outer graft layer 108 with a bonding iron, the outer graft layer. 108 can be joined to the corrugated inner graft layer 106. In another example, the outer graft layer 108 can be joined to the corrugated inner graft layer 106 using a binding material such as an adhesive or by weaving or other mechanical connection.

Therefore, the manufacture of the kink resistant graft 110 can include two separate heating cycles. A first heating cycle for joining the tube layer 102 and the film layer 104 before crushing and a second heating cycle for joining the outer graft layer 108 to the corrugated inner graft layer 106 are performed. During these heating cycles, the temperature and heating time should be controlled to obtain the desired results. In one particular example, the first heating cycle can be 250-350 ° C. between 30-60 minutes. In the same or different example, the second heating cycle can be 180-250 ° C. between 15-30 minutes. For example, temperatures that are too high can rearrange the nodes and fibril structures of the PTFE layer. It may be desirable to select a low melting point material for the outer graft layer 108 in order to limit heat exposure to the corrugated inner graft layer 106. In some examples, the material of the outer graft layer 108 is a thermoplastic copolymer, eg, the United States of Cheng et al., Named for the invention of THERMOPLASTIC FLUOROPOLYMER-COATED MEDICAL DEVICES. It can be a thermoplastic copolymer as described in Japanese Patent No. 8,048,440, the entire contents of which are incorporated herein by reference for all purposes.

As shown in FIG. 2E, when the outer graft layer 108 is adhered to the corrugated inner graft layer 106, the graft 110 is cut to the desired length and the stent elements 120, 121 are adjacent to the end of the tube of the graft 110. Can be added.

The stent graft 100 can provide one or more advantages over a stent graft that includes a stent element that extends about the entire length of the tube formed by the graft. As an example, by having fewer stent elements, the design of the stent graft 100 facilitates a lower folding profile for intravascular delivery. In addition, less stent elements also reduce the likelihood that the stent elements will wear the graft material and cause graft breakage, as the stent elements can cause wear on the graft material. Also, fewer stent elements reduce both the stiffness of the folded device and the stiffness of the expanded device, which facilitates implants through curved sections within the patient's vasculature and is also once implanted. Then you can limit the linearizing force of the device against the vessel wall.

The appended claims represent the structure, materials, elements, components, shapes, sizes and arrangements of the parts, including combinations within the principles of the present disclosure, among the examples of disclosure within the gist of the present disclosure. Various changes can be made to the full extent indicated by the broad and general meaning of the term. For example, although various exemplary configurations are provided, a number of additional configurations for kink-resistant grafts that include a corrugated graft layer that includes the retracted length as a corrugation are readily available within the spirit of the present disclosure. Can be made. Unless these various modifications and configurations deviate from the gist and scope of the appended claims, they are intended to be included therein.

The appended claims represent the structure, materials, elements, components, shapes, sizes and arrangements of the parts, including combinations within the principles of the present disclosure, among the examples of disclosure within the gist of the present disclosure. Various changes can be made to the full extent indicated by the broad and general meaning of the term. For example, although various exemplary configurations are provided, a number of additional configurations for kink-resistant grafts that include a corrugated graft layer that includes the retracted length as a corrugation are readily available within the spirit of the present disclosure. Can be made. Unless these various modifications and configurations deviate from the gist and scope of the appended claims, they are intended to be included therein.
(Aspect)
(Aspect 1)
A graft forming a tube with a central lumen extending from the first end of the tube to the second end of the tube, said graft.
The corrugated inner graft layer forming at least the middle part of the tube, and
A graft comprising an outer graft layer covering the corrugated inner graft layer.
A stent anchored to the graft adjacent to the first end of the tube,
Kink-resistant stent graft, including.
(Aspect 2)
The kink-resistant stent graft according to aspect 1, wherein the corrugated inner graft layer extends from the first end of the tube to the second end of the tube.
(Aspect 3)
The kink-resistant stent graft according to any one of aspects 1 and 2, wherein the outer graft layer extends from the first end of the tube to the second end of the tube.
(Aspect 4)
The kink-resistant stent graft according to any one of aspects 1 to 3, wherein the corrugation provides the corrugated inner graft layer with a storage length of at least 25 percent.
(Aspect 5)
The kink-resistant stent graft according to any one of aspects 1 to 4, wherein at least one of the corrugated inner graft layer and the outer graft layer is formed of a stretched polytetrafluoroethylene (ePTFE) film.
(Aspect 6)
The kink-resistant stent graft according to any one of aspects 1 to 5, wherein the outer graft layer is formed of an stretchable film.
(Aspect 7)
90 at an internal fluid pressure of at least 100 mmHg in that the graft is configured to maintain at least 60% of its cross section at the apex of a 90 degree bend while under an internal fluid pressure of at least 100 mmHg. The kink-resistant stent graft according to any one of aspects 1 to 6, which is configured to resist the kink while undergoing bending.
(Aspect 8)
The middle part of the tube between the first end and the second end does not contain any stent and the middle part is at least twice as long as the outer diameter of the tube in the middle part. The kink-resistant stent graft according to any one of embodiments 1 to 7.
(Aspect 9)
The kink-resistant stent graft according to any one of aspects 1 to 8, wherein the inner diameter of the tube is at least 12 mm.
(Aspect 10)
One of aspects 1-9, wherein the stent is a first stent, wherein the kink-resistant stent graft further comprises a second stent immobilized on the graft adjacent to the second end of the tube. The kink-resistant stent graft according to item 1.
(Aspect 11)
A method of forming a kink-resistant graft,
Wrapping the film to form an inner graft layer forming a tube with a central lumen extending from the first end of the tube to the second end of the tube,
By crushing the inner graft layer to form a corrugation in the inner graft layer, the corrugation provides a corrugated inner graft layer with a storage length of at least 25 percent.
The outer graft layer is wrapped on the corrugated inner graft layer, and the corrugated inner graft is used.
Covering the layers and
A method comprising joining the outer graft layer to the corrugated inner graft layer to form a kink resistant graft.
(Aspect 12)
11. The method of aspect 11, further comprising immobilizing a stent on the graft adjacent to the first end of the tube.
(Aspect 13)
After wrapping the film to form the inner graft layer forming the tube, the wrapped film is heated before crushing the inner graft layer to form a corrugation in the inner graft layer. 11. The method of aspect 11 or 12, further comprising curing the film in a tube.
(Aspect 14)
Aspects 11-13, further comprising wrapping the outer graft layer onto the corrugated inner graft layer to cover the corrugated inner graft layer and then joining the wrapped outer graft layer to the corrugated inner graft layer. The method according to any one of the items.
(Aspect 15)
The method according to any one of aspects 11 to 14, wherein the kink-resistant graft has a wall thickness of 0.20 nm or less.

Claims (15)

A graft forming a tube with a central lumen extending from the first end of the tube to the second end of the tube, wherein the graft forms at least an intermediate portion of the tube. Corrugated inner graft layer and
A graft comprising an outer graft layer covering the corrugated inner graft layer.
A stent anchored to the graft adjacent to the first end of the tube,
Kink-resistant stent graft, including. The kink-resistant stent graft according to claim 1, wherein the corrugated inner graft layer extends from the first end of the tube to the second end of the tube. The kink-resistant stent graft according to any one of claims 1 and 2, wherein the outer graft layer extends from the first end of the tube to the second end of the tube. The kink-resistant stent graft according to any one of claims 1 to 3, wherein the corrugation provides the corrugated inner graft layer with a storage length of at least 25 percent. The kink-resistant stent graft according to any one of claims 1 to 4, wherein at least one of the corrugated inner graft layer and the outer graft layer is formed of a stretched polytetrafluoroethylene (ePTFE) film. The kink-resistant stent graft according to any one of claims 1 to 5, wherein the outer graft layer is formed of an stretchable film. 90 at an internal fluid pressure of at least 100 mmHg in that the graft is configured to maintain at least 60% of its cross-sectional area at the apex of a 90 degree bend while under an internal fluid pressure of at least 100 mmHg. The kink-resistant stent graft according to any one of claims 1 to 6, which is configured to resist the kink while undergoing bending. The middle part of the tube between the first end and the second end does not contain any stent, the middle part being at least twice as long as the outer diameter of the tube in the middle part. The kink-resistant stent graft according to any one of claims 1 to 7. The kink-resistant stent graft according to any one of claims 1 to 8, wherein the inner diameter of the tube is at least 12 mm. Any of claims 1-9, wherein the stent is a first stent, wherein the kink-resistant stent graft further comprises a second stent immobilized on the graft adjacent to the second end of the tube. The kink-resistant stent graft according to claim 1. A method of forming a kink-resistant graft,
Wrapping the film to form an inner graft layer forming a tube with a central lumen extending from the first end of the tube to the second end of the tube,
By crushing the inner graft layer to form a corrugation in the inner graft layer, the corrugation provides a corrugated inner graft layer with a storage length of at least 25 percent.
By wrapping the outer graft layer on the corrugated inner graft layer to cover the corrugated inner graft layer,
A method comprising joining the outer graft layer to the corrugated inner graft layer to form a kink resistant graft. 11. The method of claim 11, further comprising immobilizing a stent on the graft adjacent to the first end of the tube. After wrapping the film to form the inner graft layer forming the tube, the wrapped film is heated before crushing the inner graft layer to form a waveform in the inner graft layer. The method of claim 11 or 12, further comprising curing the film in a tube. Claims 11 to 13 further include wrapping the outer graft layer on the corrugated inner graft layer to cover the corrugated inner graft layer, and then joining the wrapped outer graft layer to the corrugated inner graft layer. The method according to any one of the above. The method according to any one of claims 11 to 14, wherein the kink-resistant graft has a wall thickness of 0.20 nm or less.

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